/*
*********************************************************************************************************
*                                                uC/OS-II
*                                          The Real-Time Kernel
*                                            MEMORY MANAGEMENT
*
*                          (c) Copyright 1992-2006, Jean J. Labrosse, Weston, FL
*                                           All Rights Reserved
*
* File    : OS_MEM.C
* By      : Jean J. Labrosse
* Version : V2.84
*********************************************************************************************************
*/

#ifndef  OS_MASTER_FILE
#include <ucos_ii.h>
#endif

#if (OS_MEM_EN > 0) && (OS_MAX_MEM_PART > 0)
/*
*********************************************************************************************************
*                                        CREATE A MEMORY PARTITION
*
* Description : Create a fixed-sized memory partition that will be managed by uC/OS-II.
*
* Arguments   : addr     is the starting address of the memory partition
*
*               nblks    is the number of memory blocks to create from the partition.
*
*               blksize  is the size (in bytes) of each block in the memory partition.
*
*               err      is a pointer to a variable containing an error message which will be set by
*                        this function to either:
*
*                        OS_NO_ERR            if the memory partition has been created correctly.
*                        OS_MEM_INVALID_ADDR  you are specifying an invalid address for the memory
*                                             storage of the partition or, the block does not align
*                                             on a pointer boundary
*                        OS_MEM_INVALID_PART  no free partitions available
*                        OS_MEM_INVALID_BLKS  user specified an invalid number of blocks (must be >= 2)
*                        OS_MEM_INVALID_SIZE  user specified an invalid block size
*                                                - must be greater than the size of a pointer
*                                                - must be able to hold an integral number of pointers
* Returns    : != (OS_MEM *)0  is the partition was created
*              == (OS_MEM *)0  if the partition was not created because of invalid arguments or, no
*                              free partition is available.
*********************************************************************************************************
*/

OS_MEM  *OSMemCreate (void *addr, INT32U nblks, INT32U blksize, INT8U *err)
{
        OS_MEM    *pmem;
        INT8U     *pblk;
        void     **plink;
        INT32U     i;
#if OS_CRITICAL_METHOD == 3                           /* Allocate storage for CPU status register      */
        OS_CPU_SR  cpu_sr = 0;
#endif
#if OS_ARG_CHK_EN > 0

        if (err == (INT8U *)0)                            /* Validate 'err'                                */
        {
                return ((OS_MEM *)0);
        }

        if (addr == (void *)0)                            /* Must pass a valid address for the memory part.*/
        {
                *err = OS_MEM_INVALID_ADDR;
                return ((OS_MEM *)0);
        }

        if (((INT32U)addr & (sizeof(void *) - 1)) != 0)   /* Must be pointer size aligned                  */
        {
                *err = OS_MEM_INVALID_ADDR;
                return ((OS_MEM *)0);
        }

        if (nblks < 2)                                    /* Must have at least 2 blocks per partition     */
        {
                *err = OS_MEM_INVALID_BLKS;
                return ((OS_MEM *)0);
        }

        if (blksize < sizeof(void *))                     /* Must contain space for at least a pointer     */
        {
                *err = OS_MEM_INVALID_SIZE;
                return ((OS_MEM *)0);
        }

        if ((blksize % sizeof(void *)) != 0)              /* Must contain space for an integral number ... */
        {
                *err = OS_MEM_INVALID_SIZE;                   /* ... of pointer sized items                    */
                return ((OS_MEM *)0);
        }

#endif
        OS_ENTER_CRITICAL();
        pmem = OSMemFreeList;                             /* Get next free memory partition                */

        if (OSMemFreeList != (OS_MEM *)0)                 /* See if pool of free partitions was empty      */
        {
                OSMemFreeList = (OS_MEM *)OSMemFreeList->OSMemFreeList;
        }

        OS_EXIT_CRITICAL();

        if (pmem == (OS_MEM *)0)                          /* See if we have a memory partition             */
        {
                *err = OS_MEM_INVALID_PART;
                return ((OS_MEM *)0);
        }

        plink = (void **)addr;                            /* Create linked list of free memory blocks      */
        pblk  = (INT8U *)((INT32U)addr + blksize);

        for (i = 0; i < (nblks - 1); i++)
        {
                *plink = (void *)pblk;                         /* Save pointer to NEXT block in CURRENT block   */
                plink = (void **)pblk;                        /* Position to  NEXT      block                  */
                pblk  = (INT8U *)((INT32U)pblk + blksize);    /* Point to the FOLLOWING block                  */
        }

        *plink              = (void *)0;                  /* Last memory block points to NULL              */
        pmem->OSMemAddr     = addr;                       /* Store start address of memory partition       */
        pmem->OSMemFreeList = addr;                       /* Initialize pointer to pool of free blocks     */
        pmem->OSMemNFree    = nblks;                      /* Store number of free blocks in MCB            */
        pmem->OSMemNBlks    = nblks;
        pmem->OSMemBlkSize  = blksize;                    /* Store block size of each memory blocks        */
        *err                = OS_NO_ERR;
        return (pmem);
}
/*$PAGE*/
/*
*********************************************************************************************************
*                                          GET A MEMORY BLOCK
*
* Description : Get a memory block from a partition
*
* Arguments   : pmem    is a pointer to the memory partition control block
*
*               err     is a pointer to a variable containing an error message which will be set by this
*                       function to either:
*
*                       OS_NO_ERR           if the memory partition has been created correctly.
*                       OS_MEM_NO_FREE_BLKS if there are no more free memory blocks to allocate to caller
*                       OS_MEM_INVALID_PMEM if you passed a NULL pointer for 'pmem'
*
* Returns     : A pointer to a memory block if no error is detected
*               A pointer to NULL if an error is detected
*********************************************************************************************************
*/

void  *OSMemGet (OS_MEM *pmem, INT8U *err)
{
        void      *pblk;
#if OS_CRITICAL_METHOD == 3                           /* Allocate storage for CPU status register      */
        OS_CPU_SR  cpu_sr = 0;
#endif
#if OS_ARG_CHK_EN > 0

        if (err == (INT8U *)0)                            /* Validate 'err'                                */
        {
                return ((void *)0);
        }

        if (pmem == (OS_MEM *)0)                          /* Must point to a valid memory partition        */
        {
                *err = OS_MEM_INVALID_PMEM;
                return ((void *)0);
        }

#endif
        OS_ENTER_CRITICAL();

        if (pmem->OSMemNFree > 0)                         /* See if there are any free memory blocks       */
        {
                pblk                = pmem->OSMemFreeList;    /* Yes, point to next free memory block          */
                pmem->OSMemFreeList = *(void **)pblk;         /*      Adjust pointer to new free list          */
                pmem->OSMemNFree--;                           /*      One less memory block in this partition  */
                OS_EXIT_CRITICAL();
                *err = OS_NO_ERR;                             /*      No error                                 */
                return (pblk);                                /*      Return memory block to caller            */
        }

        OS_EXIT_CRITICAL();
        *err = OS_MEM_NO_FREE_BLKS;                       /* No,  Notify caller of empty memory partition  */
        return ((void *)0);                               /*      Return NULL pointer to caller            */
}
/*$PAGE*/
/*
*********************************************************************************************************
*                                   GET THE NAME OF A MEMORY PARTITION
*
* Description: This function is used to obtain the name assigned to a memory partition.
*
* Arguments  : pmem      is a pointer to the memory partition
*
*              pname     is a pointer to an ASCII string that will receive the name of the memory partition.
*
*              err       is a pointer to an error code that can contain one of the following values:
*
*                        OS_NO_ERR                  if the name was copied to 'pname'
*                        OS_MEM_INVALID_PMEM        if you passed a NULL pointer for 'pmem'
*                        OS_ERR_PNAME_NULL          You passed a NULL pointer for 'pname'
*
* Returns    : The length of the string or 0 if 'pmem' is a NULL pointer.
*********************************************************************************************************
*/

#if OS_MEM_NAME_SIZE > 1
INT8U  OSMemNameGet (OS_MEM *pmem, INT8U *pname, INT8U *err)
{
        INT8U      len;
#if OS_CRITICAL_METHOD == 3                      /* Allocate storage for CPU status register           */
        OS_CPU_SR  cpu_sr = 0;
#endif
        OS_ENTER_CRITICAL();
#if OS_ARG_CHK_EN > 0

        if (err == (INT8U *)0)                       /* Validate 'err'                                     */
        {
                OS_EXIT_CRITICAL();
                return (0);
        }

        if (pmem == (OS_MEM *)0)                     /* Is 'pmem' a NULL pointer?                          */
        {
                OS_EXIT_CRITICAL();                      /* Yes                                                */
                *err = OS_MEM_INVALID_PMEM;
                return (0);
        }

        if (pname == (INT8U *)0)                      /* Is 'pname' a NULL pointer?                         */
        {
                OS_EXIT_CRITICAL();                      /* Yes                                                */
                *err = OS_ERR_PNAME_NULL;
                return (0);
        }

#endif
        len  = OS_StrCopy(pname, pmem->OSMemName);   /* Copy name from OS_MEM                              */
        OS_EXIT_CRITICAL();
        *err = OS_NO_ERR;
        return (len);
}
#endif

/*$PAGE*/
/*
*********************************************************************************************************
*                                 ASSIGN A NAME TO A MEMORY PARTITION
*
* Description: This function assigns a name to a memory partition.
*
* Arguments  : pmem      is a pointer to the memory partition
*
*              pname     is a pointer to an ASCII string that contains the name of the memory partition.
*
*              err       is a pointer to an error code that can contain one of the following values:
*
*                        OS_NO_ERR                  if the name was copied to 'pname'
*                        OS_MEM_INVALID_PMEM        if you passed a NULL pointer for 'pmem'
*                        OS_ERR_PNAME_NULL          You passed a NULL pointer for 'pname'
*                        OS_MEM_NAME_TOO_LONG       if the name doesn't fit in the storage area
*
* Returns    : None
*********************************************************************************************************
*/

#if OS_MEM_NAME_SIZE > 1
void  OSMemNameSet (OS_MEM *pmem, INT8U *pname, INT8U *err)
{
        INT8U      len;
#if OS_CRITICAL_METHOD == 3                      /* Allocate storage for CPU status register           */
        OS_CPU_SR  cpu_sr = 0;
#endif
        OS_ENTER_CRITICAL();
#if OS_ARG_CHK_EN > 0

        if (err == (INT8U *)0)                       /* Validate 'err'                                     */
        {
                OS_EXIT_CRITICAL();
                return;
        }

        if (pmem == (OS_MEM *)0)                     /* Is 'pmem' a NULL pointer?                          */
        {
                OS_EXIT_CRITICAL();                      /* Yes                                                */
                *err = OS_MEM_INVALID_PMEM;
                return;
        }

        if (pname == (INT8U *)0)                      /* Is 'pname' a NULL pointer?                         */
        {
                OS_EXIT_CRITICAL();                      /* Yes                                                */
                *err = OS_ERR_PNAME_NULL;
                return;
        }

#endif
        len = OS_StrLen(pname);                      /* Can we fit the string in the storage area?         */

        if (len > (OS_MEM_NAME_SIZE - 1))            /* No                                                 */
        {
                OS_EXIT_CRITICAL();
                *err = OS_MEM_NAME_TOO_LONG;
                return;
        }

        (void)OS_StrCopy(pmem->OSMemName, pname);    /* Yes, copy name to the memory partition header      */
        OS_EXIT_CRITICAL();
        *err = OS_NO_ERR;
}
#endif

/*$PAGE*/
/*
*********************************************************************************************************
*                                         RELEASE A MEMORY BLOCK
*
* Description : Returns a memory block to a partition
*
* Arguments   : pmem    is a pointer to the memory partition control block
*
*               pblk    is a pointer to the memory block being released.
*
* Returns     : OS_NO_ERR            if the memory block was inserted into the partition
*               OS_MEM_FULL          if you are returning a memory block to an already FULL memory
*                                    partition (You freed more blocks than you allocated!)
*               OS_MEM_INVALID_PMEM  if you passed a NULL pointer for 'pmem'
*               OS_MEM_INVALID_PBLK  if you passed a NULL pointer for the block to release.
*********************************************************************************************************
*/

INT8U  OSMemPut (OS_MEM *pmem, void *pblk)
{
#if OS_CRITICAL_METHOD == 3                      /* Allocate storage for CPU status register           */
        OS_CPU_SR  cpu_sr = 0;
#endif
#if OS_ARG_CHK_EN > 0

        if (pmem == (OS_MEM *)0)                     /* Must point to a valid memory partition             */
        {
                return (OS_MEM_INVALID_PMEM);
        }

        if (pblk == (void *)0)                       /* Must release a valid block                         */
        {
                return (OS_MEM_INVALID_PBLK);
        }

#endif
        OS_ENTER_CRITICAL();

        if (pmem->OSMemNFree >= pmem->OSMemNBlks)    /* Make sure all blocks not already returned          */
        {
                OS_EXIT_CRITICAL();
                return (OS_MEM_FULL);
        }

        *(void **)pblk      = pmem->OSMemFreeList;   /* Insert released block into free block list         */
        pmem->OSMemFreeList = pblk;
        pmem->OSMemNFree++;                          /* One more memory block in this partition            */
        OS_EXIT_CRITICAL();
        return (OS_NO_ERR);                          /* Notify caller that memory block was released       */
}
/*$PAGE*/
/*
*********************************************************************************************************
*                                          QUERY MEMORY PARTITION
*
* Description : This function is used to determine the number of free memory blocks and the number of
*               used memory blocks from a memory partition.
*
* Arguments   : pmem        is a pointer to the memory partition control block
*
*               p_mem_data  is a pointer to a structure that will contain information about the memory
*                           partition.
*
* Returns     : OS_NO_ERR            If no errors were found.
*               OS_MEM_INVALID_PMEM  if you passed a NULL pointer for 'pmem'
*               OS_MEM_INVALID_PDATA if you passed a NULL pointer to the data recipient.
*********************************************************************************************************
*/

#if OS_MEM_QUERY_EN > 0
INT8U  OSMemQuery (OS_MEM *pmem, OS_MEM_DATA *p_mem_data)
{
#if OS_CRITICAL_METHOD == 3                      /* Allocate storage for CPU status register           */
        OS_CPU_SR  cpu_sr = 0;
#endif
#if OS_ARG_CHK_EN > 0

        if (pmem == (OS_MEM *)0)                     /* Must point to a valid memory partition             */
        {
                return (OS_MEM_INVALID_PMEM);
        }

        if (p_mem_data == (OS_MEM_DATA *)0)          /* Must release a valid storage area for the data     */
        {
                return (OS_MEM_INVALID_PDATA);
        }

#endif
        OS_ENTER_CRITICAL();
        p_mem_data->OSAddr     = pmem->OSMemAddr;
        p_mem_data->OSFreeList = pmem->OSMemFreeList;
        p_mem_data->OSBlkSize  = pmem->OSMemBlkSize;
        p_mem_data->OSNBlks    = pmem->OSMemNBlks;
        p_mem_data->OSNFree    = pmem->OSMemNFree;
        OS_EXIT_CRITICAL();
        p_mem_data->OSNUsed    = p_mem_data->OSNBlks - p_mem_data->OSNFree;
        return (OS_NO_ERR);
}
#endif                                           /* OS_MEM_QUERY_EN                                    */
/*$PAGE*/
/*
*********************************************************************************************************
*                                    INITIALIZE MEMORY PARTITION MANAGER
*
* Description : This function is called by uC/OS-II to initialize the memory partition manager.  Your
*               application MUST NOT call this function.
*
* Arguments   : none
*
* Returns     : none
*
* Note(s)    : This function is INTERNAL to uC/OS-II and your application should not call it.
*********************************************************************************************************
*/

void  OS_MemInit (void)
{
#if OS_MAX_MEM_PART == 1
        OS_MemClr((INT8U *)&OSMemTbl[0], sizeof(OSMemTbl));   /* Clear the memory partition table          */
        OSMemFreeList               = (OS_MEM *)&OSMemTbl[0]; /* Point to beginning of free list           */
#if OS_MEM_NAME_SIZE > 1
        OSMemFreeList->OSMemName[0] = '?';                    /* Unknown name                              */
        OSMemFreeList->OSMemName[1] = OS_ASCII_NUL;
#endif
#endif
#if OS_MAX_MEM_PART >= 2
        OS_MEM  *pmem;
        INT16U   i;
        OS_MemClr((INT8U *)&OSMemTbl[0], sizeof(OSMemTbl));   /* Clear the memory partition table          */
        pmem = &OSMemTbl[0];                                  /* Point to memory control block (MCB)       */

        for (i = 0; i < (OS_MAX_MEM_PART - 1); i++)           /* Init. list of free memory partitions      */
        {
                pmem->OSMemFreeList = (void *)&OSMemTbl[i+1];     /* Chain list of free partitions             */
#if OS_MEM_NAME_SIZE > 1
                pmem->OSMemName[0]  = '?';                        /* Unknown name                              */
                pmem->OSMemName[1]  = OS_ASCII_NUL;
#endif
                pmem++;
        }

        pmem->OSMemFreeList = (void *)0;                      /* Initialize last node                      */
#if OS_MEM_NAME_SIZE > 1
        pmem->OSMemName[0]  = '?';                            /* Unknown name                              */
        pmem->OSMemName[1]  = OS_ASCII_NUL;
#endif
        OSMemFreeList       = &OSMemTbl[0];                   /* Point to beginning of free list           */
#endif
}
#endif                                                    /* OS_MEM_EN                                 */
